Dental matrix



(No Made l.)

W. H. MARSHALL.

. DENTAL MATRIX.

No. 427,338. Patented May 6, 1890.

EATENT FFICEG IVILLIAM H. MARSHALL, OF OXFORD, MISSISSIPPI.

DENTAL MATRIX.

SPECIFICATION forming part of Letters Patent No. 427,338, dated May 61890.

' Application filed February 26, 1890. Serial No. 341,820. (No model.)

To all whmn it may concern: I

Be it known that 1, WILLIAM H. IVIARSHALL, a citizen of the UnitedStates, residing at Oxford, county of Lafayette, State of Mississippi,have invented certain new and useful Improvements in Dental Matrices, ofwhich the following is a specification.

My invention relates to that class of dental matrices in whichwedge-shaped pieces are used for holding an auxiliary sheet, plate, orstrip of metal at the side of one or more cavities in the tooth while itis being filled; and it consists in a construction and arrangement ofparts, substantially as hereinafter set forth.

Referring to the accompanying drawings, Figure 1 is a side Viewillustrating an embodiment of my invention. Fig. 2 shows several formsof separators or wedges, and Fig. 3 shows one manner of applying myinvention in actual practice. 7

My present invention is an improvement in the same general line andextension of my invention set forth in my previous application, SerialNo. 33%,383, and is adapted to be made use of in filling cavities inteeth, more especially where the sides of the teeth have de-' cayed andit is necessary to construct an artificial wall or matrix to prevent themetal or other material used in filling the cavity from being forced outby the pressure applied in plugging or hammering it into. a compact massto constitute the filling.

In my present invention the device consists of the carriers A B, each ofwhich is made substantially of the shape indicated, and each beingprovided with a hub 2 for the reception of a screw-shaft O, which ispreferably arranged to turn loosely in the hub of the carrier A, whilethe hub of the carrier B is threaded to engage the thread of thescrewshaft. This screw is provided with an enlargement or projection Iat one end, forming a shoulder, which bears against the loose jaw orcarrier, and it may be rotated by a key fitting the squared portion J orby any other means. The carriers are preferably made U- shaped, asshown, in order that the device may be turned backward or forward overthe teeth out of the way of the operator, as indicated in Fig. 3. Thefree ends of each carrier 0r j aw are provided with a screw-threaded pina Z) or other eqnlvalent means to receive and support the wedge-shapedpieces Gr, which are provided with a screw-threaded socket or othersimilar means by which they may be detachably and interchangeablyconnected to the carriers. These wedges may be of any desired form andshaped to fit the contours of the different teeth, and many differentshapes and forms may be provided, and each onehas means foroattaching itto the carrier, so that they are interchangeable. The sides of thewedges may be slightly concave or provided with wing-shaped projectionsg to cover the portion of the lingual or buccal surfaces of the teeth,and the points may be a trifle longer on one side than on the other inorder to more nearly conform to the shape of the different teeth. Thewings may be made of spring metal, so that they may more readily conformto the contour of the lingual and buccal surfaces, and,while notimpinging upon the gums, they will reach the masticating or cuttingsurfaces or edges and inclose the two adjoining teeth as two half-hoops,or, of course, one winged wedge and one of any other form may be used.

I have found that the device as above described is exceedingly usefuland convenient, especially with gold fillings, as it can be made toadapt itself closely to the cervical margin of the cavity and it doesnot have a tendency to draw away from the cavity as it is tightened, andthe contour of the tooth can be readily restored. Sometimes I find itconvenient to use in connection with it very thin pieces or strips orbands of German silver or similar flexible metal or alloy, which stripsare placed between the teeth being operated upon adjacent the cavity andheld in position by properly adjusting the wedges on the carrier andforming a support or matrix for the metal or other material with whichthe cavity is filled. If, perchance, there are two teeth adjacent eachother, each of which has a cavity, or if they each have two cavities, as

indicated in Fig. 3, I make use of the shortthin strips D D, which areplaced between the teeth, and then by applying the loops, bands, orstrips H II, which bands are bent at their ends, as indicated at thepoint it, to

fit between the ends of the strips D D, and

applying the Wedges in the manner indicated in Fig. 3, the loops andstrips canbe readily adjusted to properly bear against all four cavitiesF in the teeth E, and they can all be filled by one adjustment of thematrix. It will be observed that the U-shaped form of the car- 5 rierspermits the shaft to be turned one side or the other out of the way ofthe operator, the screws or projections a b acting as pivots for thematrix.

Many other applications of my improved matrix will suggest themselves tothose skilled in the art, and it will be seen that by making the wedgesdetachable and pivotally attachable to the carriers a great manycombinations with the strips or matrices can be formed and the deviceadjusted so as not to interfere with the work of the operator, and,however used, it is convenient, simple, and applicable to a great manyand practically all exigencies which can arise in this class of work.

WVhat I claim is 1. A matrix for dental purposes, consisting of thecarriers and means for adjusting them and independent wedge-piecesconnected to the ends of said carriers by screws, permitting 2 5 theadjustment of the carriers with relation to the wed ge-pi eces,substantially as described.

2. The combination of the carriers A B,

screw C, and wedges G, each of the latter connected to turn on the endof one of the carriers, substantially as set forth.

3. A matrix for dental purposes, consisting of a Wedge-piece providedwith flexible wings, substantially as described.

4. A matrix for dental purposes, consisting of the carriers havingwedge-pieces, the short metal strips, and the bands having bent por-NVILLIAM H. MARSHALL.

\Vitnesses:

G. R. HILL, M. A. MoN'reoMERY.

